Waldenström's
macroglobulinemia (WM) is a
neoplasm of lymphoplasmacytic cells that produces monoclonal
IgM protein. Although hyperviscosity syndrome is a common feature of WM, central nervous system (CNS) involvement in WM is rare and is known as Bing-Neel syndrome. A 60-year-old woman was referred to our hospital with bed-bound
polyneuropathy,
edema,
splenomegaly,
IgM-λ-type monoclonal
protein and CD20-positive lymphocyte infiltration in the bone marrow. She was diagnosed with WM accompanying
POEMS syndrome (
polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes) and was treated with
rituximab and
thalidomide. She achieved partial remission of WM, and
thalidomide was continued for
POEMS syndrome. She visited our outpatient clinic 6 years later with sudden onset of
vertigo and
nausea. Magnetic resonance imaging (MRI) revealed a low-density area 4 cm in diameter in her right cerebrum and right mid-brain and she was referred to our hospital. Pathological analysis of brain biopsy samples revealed
diffuse large B-cell lymphoma (DLBCL) in the CNS.
Nucleic acid sequence analysis of the VDJ region using
DNA obtained from the original WM
tumor cells and brain tissue revealed that the DLBCL cells were derived from the original WM
malignant lymphoma cells. She received five cycles of
rituximab,
methotrexate,
procarbazine, and
vincristine (R-MPV)
therapy and 23.4 Gy of whole-brain irradiation followed by two cycles of high-dose
cytarabine, which resolved her neurological symptoms in association with reduction of
IgM levels to 367 mg/dL. MRI and computed tomography of the brain demonstrated complete remission of her CNS
lymphoma.